Method and apparatus for filling flashbulbs



7 1956 s. R. BENNETT EI'AL: I 2,772,703

METHOD AND APPARATUS FOR FILLING FLASHBULBS Filed 001:. 26. 1950INVENTORS SEDGWICK R..BENNETT kLEN MERTZ United States Patent METHOD ANDAPPARATUS FOR FILLING FLASHBULBS Application October 26, 1950, SerialNo. 192,224

15 Claims. (Cl. 141-1) This invention relates to a method and apparatusfor introducing filamentary material into a container. Moreparticularly, it relates to a method and apparatus for introducing anddistributing a metallic filamentary material such as shredded foil intoflashlamp envelopes.

The method of introducing and distributing either long single strands ofwire or short lengths of shredded foil into flashlamps aided by a movingcurrent of air is well known to the art, and has been described, forexample, in Korver Patent Number 2,115,423, and Geiger and DavidsonPatent Number 2,347,046. In accordance with the Korver patent the wireis sucked into a tube by means of a vacuum created with a venturi andthen propelled through a tube by the current of air passing therethroughwhereuponthe wire is distributed in the bulb area of the flashlamp byrecurrent air flow. In the Geiger and Davidson patent a suction means isused on the far side of the flashlamp. However, the results are quitesimilar in that the shredded foil is sucked into a tube and carriedtherein into the flashlamp where the shreds are distributed by therecurrent flow of air as the air leaves the vessel and proceeds to thepoint of suction leaving the shredded particles distributed in theflashlamp envelope. Although the methods shown and described in theabove noted patents have given reasonably acceptable results with singlestrand wire or with fills made of a single size shredded filament,considerable difiiculty has been encountered in the art when attemptswere made to use these processes in the manufacture of a focal planetype of flashlamp. These focal plane lamps are made with the use of twodifferent gauges of materials wherein the cross section of one is muchcoarser than the cross section of the other. The fills are introducedseparately in such a manner that the coarse fill occupies the upper partof the bulbous portion of the bulb, and the fine fill occupies the spaceimmediately beneath, and surrounds or is adjacent to the igniting means.When attempts were made to make this type of lamp with the fillingdevices of the prior art it was virtually impossible to obtain lampshaving uniform distribution of fill and, therefore, exhibiting uniformignition time, without resorting to additional work' operations.Furthermore, even in the case of lamps having only one type of fill itwas frequently diflicult to obtain the desired uniform distributionwithout resorting to a separate flufiing operation in which the shreddedfill was redistributed with the aid of a blast of air.

It is, therefore, an object of this invention to provide a method andapparatus for improving the technique of filling and distributingfilamentary materials into containers such as, for example, flashlampenvelopes.

It is a further object of this invention to provide a method andapparatus adapted to fill flashlamp envelopes with filamentary materialof various sizes automatically while maintaining uniform distribution.

It is a further object of this invention to provide a method andapparatus for filling focal plane type lamps automatically with twogauges of filamentary material,v

ice

while maintaining proper distribution in each, avoiding mixing of thetwo, and placing each in its proper location.

We have found that some of these objects and other advantages can beobtained in accordance withour invention by shaping the nozzle whichdelivers the fill into the container to setup eddy currents within theflashlamp.

It has been further found that this feature can be further improved uponso as to accomplish all of the above objects by giving this nozzle arotary motion.

In the drawings which illustrate preferred embodiments of the apparatusof this invention Figure 1 is a side elevation partly in section of therelevant portion of the apparatus showing a tube in which the shreddedparticles are being carried toward the flashlamp envelope, an air motorand a revolving nozzle feeding the shredded particles into a flashlampenvelope, together with representa-. tive parts of the shredding anddelivery system.

Figure 2 shows a back elevation partly in section of the air motor shownin Figure 1.

Figure 3 is a side elevation partly in section showing a mechanism ofthe type illustrated in Figure l being provided, however, with anelectric motor rather than an air motor.

The unique filling nozzle which has been found to giveextremelysatisfactory results in producing uniformly distributed fill inflashlamp envelopes is illustrated in the: drawings at 10. This nozzleis preferably made of a piece; of straight brass tubing about flt- /z"outside diameter; The one end 12 of the nozzle shown is adapted forsecuring it to a rotary driven hollow shaft of substantially the sameinside diameter by means of a coupling collarof a: type shown at 14. Theother end of the nozzle which feeds the shredded particles into theenvelope is formed about 30 and then cutting off the projecting edge ofthe tubing. This end is, for example, shown at point 15 of the drawing.A nozzle of this type can readily be used in its non-rotating form inthe filling of flashlamp envelopes to obtain substantially uniformdistribution of the fill in the envelope. If the non-rotating nozzle isinserted to a point within the envelope so that the shredded particlesstrike the inside of the bulb neck near its juncturewith the bulbousportion of the envelope the shredded particles will rebound into theinside of the bulb itself. This results in far fewer rejects for failureto obtain uniform distribution than would be the case if a straightnozzle were used. Furthermore, it helps to reduce the variability andimproves the average quality of fill.

However, when the improved nozzle hereinabove described is used inconjunctionwith a spinning mechanism it has been found to furtherimprove the quality of the product produced and has even been found tobe adaptable for use in thefilling of focal plane type lamps which usetwo separate fills differing in gauge. In its essen tials the improveddevice consists of a nozzle having a curved delivery end and a spinningdevice for rotating the nozzle during the period in which the shreddedparticles are being delivered to the envelope. ferred exampleillustrated in Figure 3 of the drawings the nozzle is caused to rotateby'means of an electric motor 20 provided with a hollow shaft 22 coupledto the nozzle 10 by means of sleeve 14 and set screws 13. The receiv ingend of the hollow shaft 22 of the motor is provided with a funnel-likeelement 24 detachably secured to it by means of set screw 25. The motorand its attached r0tat ing nozzle and funnel is so positioned withrespect to thedelivery tube 30 in preferred embodiments of thisinvention that an air gap which may vary from zero to 2" is source offilamentary material which is illustrated in this,

In the precase. as a. rotary cutter where. the foil used in making fillis shredded. In the illustrated embodiment the air current carrying theparticles in tube 30 is developed means of a'ventui'i assembly 40'.However, 1t,1S' 1I1'lq11BS tionablyi true that the rotary nozzle canvbellSedfV Vlih equala'dvanta'ge if the suction head"'pr'o viding the antcurrent is. positioned at a point beyond the fiashlamp envelope if'these elements are adapted for use withthe appa ratus' as shown inGeiger and Davidson Patent Number The embodiment illustrated in Figure lof the drawings differs only from that shown in Figure 3 indie means forrotating the nozzle. In this case the hollow shaft'50, of which a funnelis a part, togetherwith nozzle 58,-is driven by an air jet provided by ablast of air supplied through air line 60, valve 62 and nozzlefiii.Valve 62 provides means for regulating the amount of air siipply. andcontrolling the speed of the rotating shaft 50. The air from nozzle 64'is made to impinge on milledslots 57 provided on the outside edge of thefunnel 56 as shown in Figure 2. The funnel and hollow shaft being setin' ball bearings 70 and mounted on a bracket 72 enables the tube to bepositioned appropriately with respect to the tubing 74 through which theshredded particles are supplied.

In some cases it has been found desirable to insert the rotary nozzlefarther into the bulb than is desirable whenthe stationary bent'nozzleis used. This insures even distribution and keeps all the shreddedparticles within the bulb.

While operating speeds ranging between 1750 R. P. M. and-4800 R. P. M.have been used successfully it has been found that speeds in thevicinity of 2100 R. P. are most desirable if the best all-around resultsare to be obtained.

The air gap between the funnel and the delivery tube has been found tobe essential in those cases in which the'venturi means of propelling theshredded particles is used; It has, for example, been found that if thegap between the funnel and the delivery tube is too small more airreaches the lamp envelope than can be tolerated in the production offluify fills. By regulating the air gap any compacting tendency can beavoided. As has been indicated hereinabove at the preferred speed ofapproxi mately 2100 R. P. M. the air gap ranges from zero toapproximately 2'". This has been found to vary with the pressure of theair Within the carrying tube and with the type of fill being made. Thisair pressure may also vary over rather wide limitations. However, forbest results it has been found that air pressures of about 6 to poundsare considered suitable for the even distribution of extremely fineshredded particles,for example, one part of the charge at the focalplane lamps. In other types of lamps the recommended air pressure iscloser to pounds, and in a few types it may run-to pounds.

When the apparatus of the typeshown in the drawings and described in thespecification is madeuse of to fill photofiash lamps the foil 80' fromwhich fill is made as shown in Figure 1 is fed into the rotary cutter82, which cuts off strips or shredded particles which arethen picked upin-a pickup-shoe $4 and sucked into tube 86 by the actionpf the venturi88 and pushed through delivery tube 74.; The shredded particles are thenchargedinto the ;revolvirlg funnel 56 andpassed on downthrough-the'hollow shaft 50, and are ultimately discharged from thecurved end ofthe nozzle 58 within the glass envelope 90.

In those cases in which the rotary nozzle is to be used' for fillingfocal plane lamps the rotary cutter is adjusted so as tocut relativelycoarse shreds; These are fed into the fiashlamp envelope by means of therotarynozzle'which' is; placed close to the mouth of thefiashlampenvelope permits the shredded particles to be, evenlydistributed the top: half of the flsh1ainp nve15pe Another rotary;cutter is adjusted to cut relativelyffih shre another rotary, nozzlewhich has been well insertedinto the lamp so that the fine particles aredeposited in an evenly distributed fiuffy manner near the entrance tothe bulb.

In those cases in which the rotary nozzle is to be used in themanufacture of single gauge types of fiashlamps a single rotary cutteris adjusted to cut the requiredwsize and number of'shreds which are thenfed into the flashlamp envelope by means of the rotary nozzle insertedWell within the lamp. The positioning of the nozzle well within theenvelope and off the axis of the neck of the envelope serves to promotea fill mass rotation'witliin the envelope during the fill cycle. Anozzle rot-ationin the vicinity of 2100 R. P; M. helps maintain thisfill mass rotation, which in turn is an aid in the production of strongwell knit fills, evenly distributed throughout the bulb area.

While the above description and drawings submitted herewith disclosepreferred and practical embodiments 'of the method and apparatus forintroducing filamentary:

material into flashlight envelopes it will be understood by thoseskilled" in the art that the specific details of'c'on struction andarrangement of parts as shown and described are byway of illustrationand'are not to be construed as limiting the scope of the invention.

What we claim is:

1. In an apparatus for use in introducingand arrang ing filamentaryparticles in a flashbulb envelope, means for supportinga flashbulbenvelope, means comprising.

conduits for transporting filamentary particles .in a gas stream from asource of supply tov said envelope, said conduits including a tubularnozzle having a delivery end.

bent atan angle adapted to project the filamentary par ticles therefromto one side of the tube axis, said bent end having no partsprojectingbeyond the cylindrical walls of the tube, the axis of the nozzle beingarranged to'be offsetfromthe' axis of the tube.

2. Inan apparatusfor use in introducing and arrange ing filamentaryparticles in a fiashlamp envelope, an electrically driven motor having ahollow shaft, a nozzle at oneend' ofsaid shaft having a deliveryopening" in the side: wall thereof adapted to project filamentary particles therefrom to one side of the axis of rotation of said hollowshaft, and means for upporting a flashbulb in position to receive saidnozzle along an axis offset from the axis of the flashbulbs.

3'. In a n' apparatus for use in introducing and -arrang' ingfilamentary particles in a flashbulb envelope, the combination of adelivery tube adapted to carry filamentar particles therethrough bymeans of a current of:

air, siaid tube having amend, a funnel-like element spaced from said endin position to receivefilamentary .particles projected from saiddelivery tube and'a tubular nozzle connected to said funnel and adaptedto project filamentary particles therefrom directly toward; the inside"sidewall of said' envelope. I

41 In an apparatus for use in introducing-- and arrangin'g. filamentaryparticles in a; flashbulb envelope, the combination of a delivery tubeadapted to carry filamentary particles therethrough by means of acurrent of air, said tube having an end, a funnel like element spacedfrom said end position toi receive filamentary particles", projectedfrom said, delivery tube, and rotatable nozzle connected to said funneland adapted to project (filamentary particles therefrom. v

5. In an apparatus for use. in introducing and; arranging filamentary?particles a flashbulb envelope, the combination of a delivery tubeadapted to carry fila-j mentary particles therethrough by means of acurrent of a ii' saidtubehaving an end, a funnel-like element spacedfrom said end in position to receive filamentary par: ticles proeated'rrom' said delivery tube, a hollow shaft connected to the. smalllend of said funnel-dike element,

means for rotating said. hollow shaft and ac nozzle" at th e' 'far endsaid shaft having-a delive y opening ifi'th side wall thereof adapted toproject filamentary particles therefrom to one side of the axis ofrotation of said hollow shaft.

6. In an apparatus for use in introducing and arranging filamentaryparticles in a flash-bulb envelope, the combination of a delivery tubeadapted to carry filamentary particles therethrough by means of acurrent of air, said tube having an end, a funnel-like element spacedfrom said end in position to receive filamentary particles projectedfrom said delivery tube, a motor driven hollow shaft connected to thesmall end of said funnellike element and a nozzle at the far end of saidhollow shaft having a delivery opening in the side wall thereof adaptedto project filamentary particle therefrom to one side of the axis ofrotation of said hollow shaft.

7. In an apparatus for use in introducing and arranging filamentaryparticles in a flashbulb envelope, the combination of a delivery tubeadapted to carry filamentary particles therethrough by means of acurrent of air, said tube having an end, a funnel-like element spacedfrom said end in position to receive filamentary particles projectedfrom said delivery tube, a hollow shaft connected to the small end ofsaid nozzle, said hollow shaft being the shaft of an electric motor anda nozzle at the far end of said hollow shaft having a delivery openingin the side wall thereof adapted to project filamentary particlestherefrom to one side of the axis of rotation of said hollow shaft.

8. In a method for introducing and arranging fil amentary material in aflashbulb envelope, the steps comprising moving filamentary particlesthrough a delivery 'tube by means of an air current, said tube having anend, projecting the filamentary particles from said delivery tube into afunnel-like element attached to a hollow rotating shaft, carrying saidfilament particles through said hollow rotating shaft and into a nozzleattached to said shafit by means of a gaseous current of air, projectingsaid filamentary particles from said nozzle toward the side walls of aflashbulb envelope whereby said particles are distributed and arrangedWithin said envelope while permitting the gaseous carrying medium toleave said envelope through its neck portion.

9. In a method for introducing and arranging filamentary material in aflashbulb envelope, the steps comprising projecting filamentaryparticles from a rotating nozzle toward the side walls of a flashbulbenvelope with the aid of a moving gaseous medium whereby said particlesare distributed and arranged within said envelope, and withdrawing thegaseous carrying medium from said envelope through its neck portion.

10. In a method for introducing and arranging filamentary material in .aflashbulb envelope, the steps comprising moving filamentary particlesthrough a delivery tube by means of an air current, said tube having anend, projecting the filamentary particles from the end of said deliverytube into a funnel-like element from said delivery tube into afunnel-like element attached to a hollow rotating shaft carrying saidfilamentary particles through said hollow rotating shaft and into anozzle attached to said shafit by means of a gaseous current of airprojecting said filamentary particles from said nozzle into a flashbulbenvelope whereby said particles are distributed and arranged within saidenvelope, and permitting the gaseous carrying medium to leave saidenvelope through its neck portion.

11. In an apparatus for use in introducing and arranging filamentaryparticles in 'a flashbulb envelope means for supporting a flash-bulbenvelope, means comprising conduits for transporting filamentaryparticles in a gas stream from a source of supply to said envelope, saidconduits including a tubular member adapted to receive and transportfilamentary particles and a tubular nozzle in communication therewithhaving a delivery opening in the side wall thereof and a curved wallsurface at its end adapted to project the filamentary particle therefromto one side of the tube axis.

12. In an apparatus for use in introducing and arranging filamentaryparticles in a flashbulb envelope means for supporting a flashbulbenvelope, means comprising conduits for transporting filamentaryparticles in a gas stream from a source of supply to said envelope, saidconduits including a tubular member adapted to receive and transportfilamentary particles, and a tubular nozzle having a delivery opening inthe side walls thereof and a curved wall surface at its end bent at anangle of approximately 30 and adapted to project the filamentaryparticles therefrom to one side of the tube axis.

13. In an apparatus for use in introducing and arranging filamentaryparticles in a flashlamp envelope, the combination of: a delivery tubeadapted for connection to a source of air under pressure at one end andhaving its other end open; another tube in communication with a sourceof filamentary particles and connected to the side of said delivery tubebetween the ends thereof so that filamentary particles from said othertube will be carried into and through the delivery tube; a funnellikeelement spaced longitudinally from the open end of said delivery tube toreceive filamentary particles emerging therefrom; a hollow shaft incommunication at one end with said funnel-like element to receive thefilamentary particles from said funnel-like element; means for rotatingsaid hollow shaft; a nozzle at the other end of said hollow shaft, saidnozzle having a delivery opening in the side wall thereof through whichsaid filamentary particles can be projected; and means for supporting aflashbulb in position to receive said filamentary particles against theside of said bulb.

14. The combination of claim 13, in Which the means for supporting theflashbulb supports said bulb with the axis thereof offset from the axisof said nozzle.

15. In an apparatus for use in introducing and arranging filamentaryparticles in a flashbulb envelope, means comprising conduits fortransporting filamentary particles in a gas stream from a source ofsupply to said envelope, said conduits including a hollow member adaptedto receive and transport filamentary particles and a nozzle incommunication therewith for projecting said filamentary particles in adirected stream, and means for supporting a flashbulb envelope on anaxis offset from the axis of the discharge end of the nozzle and inposition to receive said stream directly on the inside sidewall of saidenvelope.

References Cited in the file of this patent UNITED STATES PATENTS2,115,423 Korver Apr. 26, 1938 2,347,046 Geiger Apr. 18, 1944 2,353,031Hartline July 4, 1944 2,414,138 Bruchner Jan. 14, 1947 2,500,400Cogswell Mar. 14, 1950

